1. Field of the Invention
Metal working, especially machines for applying metal barrel heads to metal barrels.
2. Description of the Prior Art
The seaming of barrel heads on metal barrels is well known and a typical machine is disclosed at least as early as U.S. Pat. No. 1,486,974 issued to Lindgren on Mar. 18, 1924. The procedure for bending the metal around the periphery of a metal barrel and forming a double seam from cam operated seamer rolls brought into engagement with the material is well known and is discussed in numerous publications and patents including "EVALUATING A DOUBLE SEAM", a bulletin distributed by Dewey and Almy Chemical Division, W. R. Grace and Company, Cambridge, Mass. Of course, cans and barrels vary as to the size and material and the forming of the seams vary accordingly. However, the procedure insofar as the making of the double seam is concerned is basically disclosed in the Lindgren patent. In the Lindgren machine and known prior art machines the chuck ring which supports the cover and barrel during the seaming operation on both ends of the barrel are driven from a common drive shaft in a substantially rigid mechanical drive arrangement. This arrangement of direct mechanical drive does not permit any differential between chucks and requires that the chuck rings be driven substantially at the same speed and at the same time which has been believed to be a criteria for a proper operating machine. These prior machines provide a normal speed of the chucks at approximately 180 to 240 r.p.m. If any appreciable differential in speed develops due to mechanical wear a seaming problem may develop. Any higher speeds produce excess load on the clutch and brake and the gear noise is too high. In fact, older machines in present day use are so noisy as to be unacceptable by certain noise standards promulgated according to Government regulations. Also, the controls for the machine were basically all mechanical and were limited as compared with electrical or hydraulic-electrical control combinations. The independent drive arrangement of the present machine makes it possible to increase the speed without increasing the noise and to bring the overall noise of the machine down to a lower level. In addition, the present method of roll forming the double seam through independent drive on each chuck eliminates any problem previously caused by the dependent straight drive mechanical relationship between the roll forming on opposite ends. Furthermore, in some instances of seaming only one chuck need be driven and the other one can be idling or a slave which is caused to seam movement of the drum.